Table 1. Main demographics and stimulation parameters of each group.
Parameters	Group 1	Group 2	Group 3	Group 4	p-value
	P4i ≤ 1.5 and P4 f ≤ 1.5	P4i ≤ 1.5 and P4 f > 1.5	P4i > 1.5 and P4f ≤ 1.5	P4i > 1.5 and P4 f > 1.5
	350	51	11	6
Nº Cycles	393	51	11	6
Female age	34.14 ± 2.92 (25 – 38)	33.58 ± 2.87 (28 – 38)	33.81 ± 3.06 (27 – 38)	32.83 ± 2.40 (29 – 35)	NS
Basal FSH (UI/ml)	6.91 ± 5.74	5.96 ± 2.95	6.58 ± 2.47	5.00 ± 1.92	NS
Basal Estradiol (pg/mL)	72.95 ± 79.13	72.12 ± 56.93	54.36 ± 25.10	64.16 ± 55.32	NS
Basal P4 (ng/mL)	474.48 ± 260.81abc	751.41 ± 317.72ad	2844.18 ± 1477.10cd	3586.16 ± 2223.30b	abcd< 0.05
N. follicles ≥ 18 hCG day	2.76 ± 1.60ab	4.39 ± 3.16a	2.45 ± 1.29	5.00 ± 1.54b	ab< 0.05
Total gonadotropins (IU)	2016.40 ± 717.25a	2228.92 ± 701.74	2844.18 ± 1477.10a	2416.66 ± 358.35	a< 0.01
Duration of stimulation	9.65 ± 1.59	10.23 ± 1.54	9.72 ± 2.05	10.00 ± 0.63	NS
Endometrium thickness ET day	10.58 ± 5.06	10.43 ± 2.14	10.40 ± 2.88	10.51 ± 1.32	NS
NS: Not significant.